Structural components and/or other materials may be tested to determine their material characteristics. Determining the material characteristics of a structural component and/or material may be important in determining, for example, whether or not that component or material is suitable for a particular use. In some tests, a specimen that is representative of a particular structural component and/or material may be selected. During the test, one or more forces may be applied to the test specimen to determine the characteristics of that specimen. In some tests, one or more forces may be applied to induce and/or propagate a crack in the test specimen. In those tests, measuring the crack length and the associated load provides information regarding the material characteristics of the test specimen. An example of a material characteristic that may be calculated based on the crack length and associated load is the strain energy release rate.
X-ray imaging equipment has been used to detect and measure cracks in test specimens. The X-ray imaging equipment can capture and process a limited number of images over a particular time period, such as about one image over a three-second period. Additionally, the cracks shown on the X-ray images typically are manually measured by a person using a ruler or tape measure (either physical or digital). Material characteristics are then calculated based on the measured crack length.
However, material characteristics of a test specimen may not be accurately determined or calculated using the above method. For example, only a limited number of X-ray images may be obtained during propagation of a crack in a test specimen as compared to the speed of a digital camera. Additionally, the cracks in the X-ray images may not be accurately measured by a person using a ruler; because x-ray images consist of averaged frames, there may be no clear indication of where a crack ends. Inaccurate determination of material characteristics may lead to selection of a component or material that is not suitable for its intended use, which may lead to premature failure of that component or material while in service.